Various types of communication equipment, typically car radios, car radio-cassette recorders and the like, have control elements which should be readily operable even though the interior of the vehicle is dark. The various operating elements should be easily and readily accessible and so indicated that finding the respective position of a selected control element is simple and can be determined by visual checking, without relying, only, on "feel". It is well known to install light guides on the front plate of a car radio above the operating elements which carry, at the front, an opaque coating or cover with the respective functions left off, or being transparent, so that the control buttons located beneath the light guide which carries the operating indicia can be easily determined. This arrangement, however, does not positively locate the control buttons which, then, must be found by "feel" if there is no other external illumination available. Arrangements in which light guides provide indication of the function of selected control buttons are difficult to operate in darkness, particularly without distractihg the driver of the vehicle from traffic conditions, rather providing for the driver a clearly marked operating location to press a selected button, for example. In the dark, such buttons cannot be found visually.
It has previously been proposed to supply light guides to the operating buttons themselves, in which the function indications are shown on the buttons themselves. Such arrangements permit immediate accessing of the specific buttons by the operator, for example by an operator's finger, but are complex to make due to the required light coupling to the respective buttons. The additional cost and complexity of such arrangements usually is not warranted.